A former Diavik Diamond Mines Inc. employee accused of stealing rough stones worth thousands of dollars pleaded guilty to theft in a Yellowknife courtroom Monday.

Samson Mkhitaryan, 40, pleaded guilty to one count of theft over $5,000 in NWT Supreme Court.

Mkhitaryan, an ex-employee at the Diavik diamond sorting plant located near the Yellowknife airport, was charged in March after security at the facility reported the suspected theft of diamonds to . It's alleged Mkhitaryan pocketed pricey stones between December 2017 and February 2018.

Investigating Mounties were shown surveillance footage of a man, alleged to be Mkhitaryan, placing uncut diamonds into his pocket while on the job, according to court documents.

Police say a search of Mkhitaryan's residence in March, detailed in search warrant documents - not yet been tested in court - led to the recovery of 29 rough diamonds from his garage.

Mkhitaryan will be back in court on Dec. 17 to set a date for sentencing.